1. Field of the Invention
This invention relates to the field of continually variable automatic transmissions. More particularly, the invention pertains to a technique for adjustably transmitting the position of a pulley sensor to hydraulic valves that control operation of the transmission.
2. Description of the Prior Art
A device for adjusting the control input to a valve arrangement that produces fluid pressure as a function of position is known from European Patent Specification No. 0,158,370. There, a lever system transmits the position of a cone-pulley in a belt-driven transmission to the valve arrangement. The operating position of the pulley is set and adjusted by a setting thread located inside the levers.
This adjustment device has the disadvantage that, in order to change the operating position of the lever system, part of the lever system located inside the transmission or the valve body must be accessible to the operator making the adjustment by removal of the oil sump that supplies the valve body with oil.
Because of this, it is impossible to change the position of the lever system when the automatic transmission is in operation. This deficiency results in repeated setting procedures while the transmission is inoperative made on the basis of setting checks taken and recorded during its operation.
German Offenlegungsschrift No. 15 30 775 describes a setting device for a valve arrangement of an automatic transmission in which fluid pressure is produced as a function of position parameters. The operating position of the valve can be altered and set during operation of the transmission by a key or tool inserted from outside the transmission housing. In this way, the effect of the changed setting on transmission functions can be checked directly.